<template>
  <div class="sub-category">
    <div class="container">
      <!-- 面包屑 -->
      <SubBread />
      <!-- 筛选区 -->
      <SUbFilter @filter-change="changeFilter" />
      <!-- 结果区域 -->
      <div class="goods-list">
        <!-- 排序 -->
        <SubSort @sort-change="changeSort" />
        <!-- 列表 -->
        <ul>
          <li v-for="goods in goodsList" :key="goods.id">
            <GoodsItem :goods="goods"/>
          </li>
        </ul>
        <!-- 加载组件 -->
        <XtxInfiniteLoading :loading="loading" :finished="finished" @infinite="getData" />
      </div>
    </div>
  </div>
</template>

<script>
import SubBread from './components/sub-bread'
import SUbFilter from './components//sub-filter'
import SubSort from './components/sub-sort'
import GoodsItem from './components/goods-item.vue'
import { findSubCategoryGoods } from '@/api/category'
import { ref, watch } from 'vue'
import { useRoute } from 'vue-router'
export default {
  name: 'SubCategory',
  components: {
    SubBread, SUbFilter, SubSort, GoodsItem
  },
  setup () {
    const route = useRoute()
    // 加载中
    const loading = ref(false)
    // 是否加载完毕
    const finished = ref(false)
    // 商品列表数据
    const goodsList = ref([])
    // 请求参数
    let reqParams = {
      page: 1,
      pageSize: 20
    }
    // 获取数据
    const getData = () => {
      loading.value = true
      // 设置二级分类的id
      reqParams.categoryId = route.params.id
      findSubCategoryGoods(reqParams).then(({ result }) => {
        // 获取数据成功
        if (result.items.length) {
          // 有数据就追加数据
          goodsList.value.push(...result.items)
          // 把 page 改成下一页页码
          reqParams.page++
        } else {
          // 没有数据,代表加载完毕
          finished.value = true
        }
        loading.value = false
      })
    }
    // 在更改了二级分类的时候需要重新加载数据
    watch(() => route.params.id, newVal => {
      if (newVal && `/category/sub/${newVal}` === route.path) {
        finished.value = false
        goodsList.value = [] // 导致列表为空 加载更多组件顶上来 进去可视区 去加载数据
        reqParams = {
          page: 1,
          pageSize: 20
        }
      }
    })

    // 1. 更改筛选组件的筛选数据，重新请求
    const changeFilter = filterParams => {
      finished.value = false
      // 合并请求参数 保留之前参数
      reqParams = { ...reqParams, ...filterParams }
      reqParams.page = 1
      goodsList.value = []
    }

    // 更改排序组件的筛选数据 重新请求
    const changeSort = sortParams => {
      finished.value = false
      // 合并请求参数 保留之前参数
      reqParams = { ...reqParams, ...sortParams }
      reqParams.page = 1
      goodsList.value = []
    }
    return { loading, finished, getData, goodsList, changeFilter, changeSort }
  }
}
</script>

<style lang="less" scoped>
.goods-list {
  background: #fff;
  padding: 0 25px;
  margin-top: 25px;
}
ul {
  display: flex;
  flex-wrap: wrap;
  padding: 0 5px;
  li {
    margin-right: 20px;
    margin-bottom: 20px;
    &:nth-child(5n) {
      margin-right: 0;
    }
  }
}
</style>
